The Gladiator was driven off the lot with this problem. Because of Winter, windows were closed during test drive. On the way home I did open the windows and then with successive testing, I found the issue to be at the exhaust flange between exhaust header system and muffler system.
The video below shows where the leak is along the length of exhaust system. At around the 30 second mark it is clear where the leak is.
Here’s the assembly from a Mopar picture. It is at item #10.
Picture of the clamp before removing it:
After getting approval from the service manager, I removed the clamp to attempt to readjust it. I first tried to tighten it, but it was already tightened as far as it could go.
Part 1 of 2 – it looks like the design on the mating between the pipes is not great. This joint did not spread after removing the clamp. It looks like the silver flange is not long enough to seal well enough on the bronze looking flange. The clamp itself is specifically located by that welded on tab (I used a screwdriver to lift the locking mechanism).
Part 2 of 2
Here’s a top view of the pipe. It is too close to get an in focus shot, but note the highlighted area. That is just about where the jaws of the clamp close. There is a void at the seam which will let gasses out, regardless of the clamp.
When replacing the clamp I tried to pull the muffler pipe closer to the flange, but could not. As I mentioned previously, the ill fitment of these two pipes is almost exactly as it was when I removed the clamp.
I also tried shifting the clamp back and forth as you can see in the picture below. It “helped”, but did not solve the problem. I also reinstalled the clamp with the bolt head on the bottom just to make it easier for the next guy to remove it. Again, it is quieter than it was, but gas is still escaping and the clamp in this position will probably work loose.
Conclusions:
- The flange connection design is not great
- There’s a void in the silver muffler pipe
- It might be possible to shift the muffler assembly forward to get a better seal, but there’s still that void in the silver pipe to deal with